Benjamin f



(No Model) I B. F. 8; F. B. MARTINDALE.

REVERSIBLE SCREW MEGHANIGAL POWER. 7 No. 585,825. Patented July 6, 1897.

I I IM A @inmmo screw or cylinder.

UNITED STATES BENJAMIN F. MARTINDALE AND FRANKLIN B. MARTINDALE, OF WICl-IITA,

KANSAS, ASSIGNORS or PLACE.

ONE-HALF TO RODOLPH HATFIELD, OF SAME REVERSIBLE-SCREW MECHANICAL POWER.

SPECIFICATION forming part of Letters Patent No. 585,825, dated July 6, 1897.

Application filed. September 22,1896. Serial No. 606,653. (No model.)

To all whom it may concern.-

Be it known that we, BENJAMIN F. MARTIN- DALE and FRANKLIN B. MARTINDALE, citizens of the United States of America, residing at WVichita, in the county of Sedgwick and State of Kansas, have invented certain new and useful Improvements in Reversible- Screw Mechanical Power, of which the following is a specification, reference being had therein to the accompanying drawings, and the figures of reference thereon, forming a part of this specification, in which-- Figure 1 is a side view of our improved reversible-screw mechanical power. Fig. 2 is a top plan view of the same. Fig. 3 is a longitudinal section of the same. Fig. 4 is an end view of said mechanical power. Fig. 5 is a cross-section of the same. Fig. 6 is a side view of the screw-nut, and Fig. 7 is a top plan of the same.

This invention relates to certain improvements in reversible screws for mechanical power or motion; and it consists of a cylinder or screw having screw-threads of different 2 5 depths running in opposite directions, and

a nut adapted to run in each of said screwthreads alternately, and means for adj ustably holding said nut in each of said threads.

Referring to the drawings, 1 represents the 2 represents a portion of a frame in which said cylinder is journaled.

3 represents pulley or driving wheels. 4 represents a driving head-bloek. 5 represents a standard, with the nut 6 in- 5 tegral at one end. 7 represents a coil-spring for automatically holding said nut 6 in the threads. 8 represents an arm transversely secured to said standard 5. 9 represents a spring, one end secured to the outer end of said arm 8 and the opposite end secured to the standard-support- 10. 11 represents the bearings of said cylinder 1. 12 represents a deep thread in said cylinder. 13 represents a shallow thread running in an opposite di- 5 rection and crossing said deep thread. 14 represents the long end of said nut 6, curved on one side to more readily guide said nut from one thread to the other in reversing at either end. 1

15 represents the deep thread at either end running on an incline to correspond to the depth of the shallow thread. i

16 represents a portion cutaway in the driving head-block 4 to admit of the oscillating and vertical movement of the nut 6.

17 represents a track or guide to prevent the head-block from rotating, thus compelling a lateral movement of said head-block through the medium of the screw and. nut.

18 represents a stop or pin secured to the standard 5, through the medium of which said spring 7 holds said standard and nut in the screw-threads 12' and 13.

19 represents a pin projecting out from the standard 5, and 20 represents a pin or lug secured to the sliding head-block.

The deep thread 12 makes larger number of turns around the cylinder in a given distance than the shallow thread, thus giving a larger amount of power to the driving headblock 4 when the nut 6 is in said deep screw, and a greater speed in the reverse movement when said nut 6 is in the shallow thread. The spring 7 is sleeved on said standard 5, with one end pressing against the pin 18, which is secured to the standard 5, and the opposite end pressing against the standardsupport 10, thus yieldingly holding said nut 6 in the threads 12 and 13.

The cylinder 1 is rotated through the medium of the driving-pulley 3 or its equivalent. When the nut 6 is in the deep thread and the cylinder is rotated, the driving head-block 4 will be forced from end to end of said cylinder. As shown in Fig. 1, when said headblock reaches the left end of said cylinder, the incline 15 of said deep thread, the nut 6 will yieldingly follow said thread 15, as represented by arrows in Fig. 1, to the shallow thread 13. Said nut is made longer from the standard at one end than at the other and provided with the curved and pointed end, so as to guide said nut 6 from one thread to the other at either end. Thespring 9 and arm 8 are for holding the curved end 1'1: of said nut 6 against the threads. The pins 19 and 20 are for preventing the spring 9 from drawing said nut 6 too far around.

Having thus described our invention, what we claim as new and useful, and desire to secure by Letters Patent, is as follows:

1. In a mechanical movement, the combination of a cylinder having two threads circumscribing said cylinder in opposite directions, said threads being of different depths, the deeper of said threads having an incline at each end, and terminating the same, 0011- necting it with the shallower thread, a nut adapted to alternately travel in each of said threads, and a sliding head-block adapted to yieldingly hold said nut in said threads.

2. In a mechanical movement, the combination of a cylinder having two threads circumscribing said cylinder in opposite directions and at different degrees of angle, said threads being of different depths, the deeper of said threads having an incline at each end, and terminating the same, conneotingit with the shallower thread, a head-block adapted to move laterally from end to end on said cylinder, a nut yieldingly' secured to said headblock, and adapted to ride in each of said threads, and means for guiding said nut from one to the other of said threads.

3. In a mechanical movement, the combination of a cylinder having two threads circu mscribing said cylinder in opposite directions, and at different degrees of angle, said threads being of differentdepths, the deeper of said threads having an incline at each end, and terminating the same, connecting it with the shallower thread, a head-block sleeved on said cylinder and adapted to move laterally, a nut having a standard, a coil-spring sleeved 011 said standard for yieldingly holding said nut in said threads.

IVitn esses:

FRED BROWN, RoDoLPH HATFIELD. 

